As shown in FIG. 1A, telephone calls, especially long distance calls, often involve more than one telephony carriers 110, 111, 112, 113 to complete the calls over PSTN network between an originating telephone 22 and a terminating telephone 25. Therefore, transactions are often made between an originating carrier 110 and a terminating carrier 111, or between the originating/terminating carriers 110, 111 and one or more bridging carriers 112, 113 that bridge between the originating and terminating carriers 110, 111.
With the development in Internet telephony technologies, more and more telephone calls are transmitted, at least in part, over the Internet so as to substantially lower cost. As shown in FIG. 11B, a typical phone-to-phone call, which was traditionally transmitted completely over a PSTN network, is now able to be transmitted partly over the Internet. More specifically, a call initiated from a telephone 22 is transmitted over a PSTN network 11 to an originating gateway 202, which converts the call from PSTN protocol to a packet data network protocol and transmits the call over packet data network 10 (such as the Internet) to a terminating gateway 302 where the call is converted back to a PSTN protocol and transmitted to the destination telephone 25 through a PSTN network 12. This saves cost as the gateways 202 and 302 are local to their respect telephones 22, 25, especially when the call between the two telephones 22, 25 is a long distance call or even an international call.
Originating gateway 202 and terminating gateway 302 are often if not usually owned by different carriers, and transactions have to be made between the two carriers for completing the call. In the sense of the transaction for a specific call, the owner of the originating gateway 202 is called here an “originating carrier”, and the owner of the terminating gateway 302 is called here a “terminating carrier”. It is understood that an originating carrier may be a terminating carrier, or vise versa, in other calls. In addition to terminating gateway 302, there may exist plural of other gateways that are also capable of conveying calls to (and from) the destination telephone 25 over the PSTN network 12. Moreover, there are numerous gateways that are capable of transmitting calls to other destinations (e.g., telephone 26) over other local PSTN network (e.g., PSTN 13), and the carrier that owns the originating gateway 202 may not have any transaction agreement with them or even be aware of them. Transactions of capacities are often made directly between the originating carriers and the terminating carriers.
Alternatively, to facilitate the transactions between originating carriers and terminating carriers, a telephony system 100 may be provided to broker the capacities. More specifically, the telephony system buys capacities from carrier suppliers (e.g., the owners of terminating gateways 301-304) and sell them to the originating carriers (e.g., the owner of originating carrier 202), wherein the originating and terminating carriers do not need to directly make agreements with each other, and even do not need to know each other. When a call destined to the telephone 25 is initiated at telephone 22, if the originating carrier of gateway 202 is used, the call is transmitted through PSTN network 11 to the originating gateway 202. The originating gateway 202 sends a request to the telephony system 100 for a terminating gateway to forward the call. The telephony system 100 checks a database 101 and selects a terminating gateway 301 that is capable of completing the call to the destination telephone 25. The IP address of such gateway 301 is forwarded to the originating gateway 202, for completion of the call. With the address of the terminating gateway 301, the originating gateway 202 forwards the call to the terminating gateway 301, which conveys the call to the destination telephone 25. Often, the addresses of plural terminating gateways may be forwarded to originating gateway 202, with the originating gateway 202 trying them in a prescribed order. Additionally, the communication over the Internet between the gateways may include further call related information, such as a transaction ID for each call, billing information, etc.
The originating carrier who buys call completion services either from the telephony system 100 or directly from the terminating carrier is called a “buyer” or a “carrier customer”, while the terminating carrier who sells the capacity to the telephony system 100 or directly to the originating carrier is called a “seller” or a “carrier supplier”. Thus, for each call, the transactions are made between the telephony system 100 and both the carrier customer (who owns the originating gateway) and the carrier supplier (who owns the terminating gateway), or made directly between the carrier customer and the carrier supplier.
The transactions are, however, often changed. Such changes may result from a change of the offered rates from a carrier supplier, a change in capacity demand from the carrier customers, leaving of a key carrier supplier, etc. For example, when there is a surge of demand from carrier customers to a specific destination, the carrier customers or the telephony system 100 needs to buy more capacity from the carrier suppliers that capable of handling calls to that specific destination. When a key supplier leaves or has increased its rate, the customer carrier or the telephony system 100 may need to seek capacity from new carrier suppliers. This often involves reprogramming systems manually, or other inefficient means. Therefore, there exists a need of efficiently making transactions in such systems with less human intervention and increased efficiency.